Site description
The study sites were located in the Damxung County, Xizang Autonomous Region, China (Fig. 1). The area has a continental semi-arid climate. The average annual temperature in the region is -0.8 ℃ and the annual precipitation is 403 mm (Ma et al., 2023). Alpine steppe is one of the major grassland types in this region, which were dominated by C. parvula and S. capillacea (Table S1). Other coexisting species included mainly A. szechuanensis , A. wellbyi , M. sikkimensis , P. saundersiana , and P. nivea . C. spinifera and D. fruticosa are native shrubs that widely distributed on the central Tibetan Plateau, which is becoming more abundant at alpine ecosystem in recent years (Zhao et al., 2023).